Recently, in accordance with the expansion of broadcasting services having high definition (HD) resolution in the country and around the world, many users have been accustomed to a high resolution and definition image, such that many organizations have attempted to develop the next-generation image devices. In addition, as the interest in HDTV and ultra high definition (UHD) having a resolution four times higher than that of HDTV have increased, a compression technology for a higher-resolution and higher-definition image has been demanded.
For image compression, an inter prediction technology of predicting pixel values included in a current picture from a picture before and/or after the current picture, an intra prediction technology of predicting pixel values included in a current picture using pixel information in the current picture, an entropy encoding technology of allocating a short code to symbols having a high appearance frequency and a long code to symbols having a low appearance frequency, or the like, may be used.